Topic:
Bob's Adventures in DCC

Hardware for the handheld started to trickle today. Today's package was a couple different keypads to play with. One is the same as the one Dave Bodnar used, and another one has a few more function buttons, which may lend itself to use as a controller. It is a bit larger though.

I wrote that not clearly.... does the computer hardware allow you to do n key rollover (I can see the keypads are the simple matrix type)... the reason I asked is if you can do key combinations... some systems only will recognize one button pressed, I found out my zimo allows multiple keys so I can initiate the horn, and while holding the horn button, I can add F6 which adds the doppler shift (horn or whistle)... a very cool feature...

On my nce I had F2 (toggle on off) and a dedicated momentary horn (F2) button, so this was easy to do... but on my Zimo, I only have one F2 button, and I have defined it as momentary, so I was afraid I could not leave the horn on and then hit F6, but because it has at least 1 key rollover, it worked, holding the F2 and then hitting the F6...

Anyway, it opens up some more features if you can do this..

Greg

edit for Bob's edit: That's great, opens up a few more fun things you can do. Kinda figured that it should be supported since you have the raw keyboard inputs.

This post was edited by Greg Elmassian at December 5, 2018 9:47 AM EST ____________________________________

Be sure­ to visit ­my site, l­ots of tec­hnical tip­s and modi­fications,­ and you c­an search ­for topics­ and key w­ords.

I'm looking for suggestions for a new oscilloscope. Ive been hearing good things about the Owan SDS5032E-V scope, and its a reasonable price for what it looks like it provides. I mostly want it to help me mess around with DCC, and general Arduino-y playing.

Really like the Fluke products ...yes you pay up front but they offer a lot and till you are done buying all the other stuff offered Fluke has it all in one?

Thanks for the feedback. I did manage to get outside last weekend, plug in a few things, and get DCC (and some detection, but thats another thread) working with my old Prodigy Advance that I have for my n scale stuff. I had the track from the yard exit at Burke, all the way down to the switch off to Pearce, working fairly well, with one rail on one switch that somehow I had insulated on both ends. But the loco did its thing. This is SS track that has been down for about 18 months, all I did was run a swiffer over the rail tops to clean em a bit. Not too bad.

Thread Hijack on;

I am interested in using DCC for train dectection only (battery R/C locos no flame war please) and this interests me so eagerly waiting on the thread.

How does the detection part work?

I am guessing that I will have to provide track power but at what would be the minimum voltage level required?

This is a future project but some ideas would be greatly appreciated (I have looked at Dave Bodnars laser detectors as well)

I'm well aware of the distinction Greg, but for $10 there is no reason not to have one of these if you are going to be doing logic and firmware design. They are quite the bang for the buck. As for what I do, messing with DCC and trains and R/C and stuff, I have yet to be in a situation where I needed more. But of course, your mileage may vary.

No problem Martin, but the question was about a scope, by the OP... to others reading this, they might have taken your post to mean you purchased a scope fot $10...

If your post was," hi, I don't need a scope but want a logic analyzer" (remember the topic is about low cost scopes)... that would make sense, but your post, with no other preamble implies you bought a scope, on someone else's recommendation for $10.

Not everyone here is an expert, and I think your post without stating that you did not buy a scope but something different becomes misleading... it was misleading to me, and I have a scope and a logic analyzer and years of experience in both. Can you see and/or appreciate this?

Just trying to keep it helpful to others.

Greg

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Be sure­ to visit ­my site, l­ots of tec­hnical tip­s and modi­fications,­ and you c­an search ­for topics­ and key w­ords.

Let us know what Santa brings you, always on the lookout for a good value in scopes. I actually recommend the $35 one with the LCD screen for DCC users, so they can see the distortions in the waveform, and see if they have some problem area. Don't need anything fancy to see this generalized view... basically any nasty ringing, asymmetry in the pulses, etc.

Outside on rails, super high speed transients don't go too far ha ha!

Greg

____________________________________

Be sure­ to visit ­my site, l­ots of tec­hnical tip­s and modi­fications,­ and you c­an search ­for topics­ and key w­ords.

Let us know what Santa brings you, always on the lookout for a good value in scopes. I actually recommend the $35 one with the LCD screen for DCC users, so they can see the distortions in the waveform, and see if they have some problem area. Don't need anything fancy to see this generalized view... basically any nasty ringing, asymmetry in the pulses, etc.

As an old calibration/ PMEL tech I prefer TEK for CROs and find CRT screens better than the newer digital displays, but after saying that I do own a TEK TDS 220 which is a compact little CRO that does what I need.

Thanks Graeme, but you might have missed my statement earlier that I already have a 4 channel Tek.

Yes, Tek is my choice too, and funny story, quite a few years ago I worked for Hewlett Packard, during it's heyday. Naturally we had all HP instruments in our lab. We were having an issue in some hardware, and the HP scope was really hard to get to trigger on the signal we were looking at (it was somewhat erratic). So we attempted to buy a Tek scope. Even though we were a top R&D facility, Bill Hewlett himself had to approve the purchase, and we were really grilled over the reason an HP scope would not work.

We got it and solved the problem. Tek still triggers better all these years later in my opinion.

Greg

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Be sure­ to visit ­my site, l­ots of tec­hnical tip­s and modi­fications,­ and you c­an search ­for topics­ and key w­ords.

Played a bit this weekend with some of the new hardware (Still waiting for the LCDs to show up). So I grabbed the code from Dave Bodnar's site, and started the learning curve. First I played with the various keypads. I think either the 4x4 or 5x4 will be a good one. I like the arrows on the 5x4 from a controller standpoint, so I think Im gonna start there. Its pretty easy to get the Arduino and keypad talking to each other, only needs a dozen lines of configuration, and a simple read statement. The docs for the keypad library says that they have a getKeys() function (which, if Im reading correctly, means it will do some flavor of NKRO), but I couldnt get it to work with the time I had. Probably play with it some more tonight.

I like the tactile feel and travel of the "chiclets" type keyboards vs. the "dome style" / "snap" switches. From a human perspective, you can tell your finger has moved, and that it is held down on the chiclets type, the dome types have so little travel that if you miss the slight transition, it's harder to tell. Been a number of studies on this. Of course any of them has more feedback than a touchscreen.

Greg

____________________________________

Be sure­ to visit ­my site, l­ots of tec­hnical tip­s and modi­fications,­ and you c­an search ­for topics­ and key w­ords.

Yea, I have a 4x4 keypad with real rubber buttons that I want to play with, too. I do like the "Yea, this is a button" feel of them. I'm hoping I can dig up one that has a few more buttons than just the phone keypad numbers and A-D. The other option is to use the standard 3x4 layout, and then have a separate single-line keypad for the other buttons.

Played around a bit more last night. Got the 4x4 keypad wired and working, and started to flesh out the controller code based on Dave Bodnar's. Changing things slightly, but all in all its a good base to start from since it accounts for everything.

I also fiddled around with one of the OLED displays. Theyre a bit pricey, so I probably wont use it for the controllers, but a 1.5" full color screen is enticing.

This post was edited by Bob McCown at December 12, 2018 9:29 AM EST ____________________________________